Inner Diameter: 10mm/0.39 inch;Total Height: 13mm/0.51 inch;Cylinder Outer Diameter: 10mm/0.39 inch;Cylinder Height: 10mm/0.39 inch;Base Diameter: 32mm/1.26 inch;Base Height: 2mm/0.08 inch;Mounting Hole Distance: 16mm/0.63 inch; Type: Flange Shaft Coupling, suitable for model shaft connection, perfect accessories for RC Model motor, etc. Material: Iron Plating, hardened by heat treatment, and then electroplated. Durable and insulation, make your shaft more stable, easy to install and replace. Function: A special coupler, which can fix one shaft to a plane and install other parts on the shaft easily. Double connection points fasten the coupler tightly. Package Including:4 x 10mm Flange Shaft Coupling, 8 x Fastening Screw( M4 Hex Wrench Not Included Here )